I am a few days late.
I have to agree with Paul Krugman: these debates are absolutely useless. They are meant for outreach; i.e. “spreading the word.”
Evidence? Those who already broadly agreed with Krugman’s general economic point of view thought the debate ended with a solid Krugman “domination.” If you already agreed with Ron Paul, however, he was the clear winner. I, of course, agree much more with Ron Paul. But, who you agree with is not a proper means of judging the outcome of a debate (i.e. there are objectively good arguments, even if they are wrong).
Though, if we judge the winner on the basis of who best shut the other person out, I think the obvious choice is Ron Paul. Few people have mastered the art of yelling over your opponent and hammering the same basic slogan (Glenn Beck, Peter Schiff?).